.xm-board{grid-template-columns:repeat(2,minmax(0,1fr));gap:46px 60px;max-width:34rem;margin:1rem auto .4rem;padding:4px;display:grid;position:relative}.xm-cross{pointer-events:none;width:66px;height:52px;position:absolute;top:50%;left:50%;overflow:visible;transform:translate(-50%,-50%)}.xm-cross line{stroke:var(--text-dim);stroke-width:2.5px;stroke-dasharray:5 4;vector-effect:non-scaling-stroke}.xm-cell{border:1.5px solid var(--border);background:var(--bg-surface);border-radius:10px;gap:3px;min-width:0;padding:1.35rem .6rem .45rem;display:grid;position:relative}.xm-cell-name{color:var(--text-dim);opacity:.7;font-size:.72rem;font-weight:700;position:absolute;top:.35rem;right:.5rem}.xm-cell input{border:1px solid var(--border);background:var(--bg-surface);width:100%;min-width:0;min-height:2.2rem;color:var(--text);font:inherit;border-radius:6px;padding:.25rem .45rem;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:1.05rem}.xm-cell.is-unknown{background:color-mix(in srgb, #16a34a 12%, var(--bg-surface));border-color:#16a34a}.xm-cell.is-unknown input{color:#16a34a;font-weight:700}.xm-cell.is-factor,.xm-cell.is-divisor{border-color:color-mix(in srgb, #2563eb 55%, var(--border))}.xm-solve-btn{border:1px solid var(--border);color:var(--text-dim);cursor:pointer;background:0 0;border-radius:6px;justify-self:start;padding:.1rem .45rem;font-size:.72rem}.xm-solve-btn:hover{color:var(--text);border-color:var(--text-dim)}.xm-solve-btn.active{color:#16a34a;background:#16a34a1f;border-color:#16a34a}@media (width<=480px){.xm-board{gap:34px}.xm-cross{width:40px;height:38px}}.xm-answer-row{border-top:1px solid var(--border);margin-top:.3rem;padding-top:.35rem}.xm-answer-row>strong{color:#16a34a;font-size:1.15rem}.xm-cases{margin:1.6rem 0 .6rem}.xm-cases-title{margin:0 0 .2rem;font-size:1.02rem}.xm-cases-intro{color:var(--text-dim);margin:0 0 .9rem;font-size:.9rem}.xm-cases-grid{grid-template-columns:repeat(auto-fit,minmax(min(100%,15rem),1fr));gap:14px;display:grid}.xm-case{border:1px solid var(--border);background:var(--bg-surface);border-radius:10px;min-width:0;margin:0;padding:.7rem .8rem .8rem}.xm-case-svg{width:100%;max-width:15rem;height:auto;color:var(--text);margin:0 auto .5rem;display:block}.xm-case figcaption{gap:2px;min-width:0;display:grid}.xm-case figcaption strong{font-size:.92rem}.xm-case figcaption span{color:var(--text-dim);font-size:.85rem}